For example, the conventional electroplating process can be classified into three processes, e.g., a prior treatment process, a plating process and a post treatment process. Of those processes, the prior treatment process includes a degreasing and cleaning treatment and an acid pickling process. The prior process is normally carried out in the following manner. A predetermined treatment solution is received in a specific bath vessel and heated. Then, an object to be treated is dipped in this treatment solution for a predetermined time.
Accordingly, a plurality of bath vessels and a working space large enough for them are required. This naturally increases the equipment cost. At the same time, workers are obliged to work under such an inferior working circumstance that the treatment solution is diffused and a toxic gas is generated. Moreover, a long time is required for dipping the object into the treatment solution and thus, productivity is decreased.
As one attempt to solve those problems, the present applicant has developed an electrochemical treatment method in which a supercritical substance, an electrolytic solution and a surface active agent are introduced into a reaction bath vessel, then they are subjected to electroplating treatment in an emulsion state, and thereafter, the supercritical substance is evaporated and discharged to the outside of the bath vessel. By doing so, the reaction bath vessel, the electrodes, etc. can be cleaned without a need of a cleaning solution. This method has already been filed by the present applicant under the Japanese Patent Application No. 2000-253572.
However, this conventional method has the following problems. Since a reaction bath vessel of a high-pressure container is used as a plating vessel, the object, the electrolytic solution and the supercritical substance are received in this vessel and the electrolytic solution and the supercritical substance are agitated in the vessel, a space for agitation and an apparatus for agitation is required, the reaction bath vessel becomes large and heavy and thus expensive.
In the first-mentioned conventional method and in a method of Japanese Patent Application Laid-Open No. H11-87300, as means for agitating a supercritical fluid and a chemical solution introduced into the reaction bath vessel, the reaction bath vessel is provided at the inside thereof with an agitating blade and a rotating mechanism of a substrate, or an oscillating mechanism and an ultrasonic vibrator, so that the reaction bath vessel is oscillated or vibrated.
However, the agitating blade and the rotating mechanism inevitably increase the reaction bath vessel in size and weight and thus expensive. The oscillating mechanism makes the apparatus large scaled and in addition, mechanical trouble is more likely to occur than ever. The ultrasonic vibrator is expensive and actual effectiveness of agitation is not very sure.
It is, therefore, a primary object of the present invention to provide, in order to solve the above problems and further improve the previously-mentioned electrochemical treatment method and an apparatus thereof, a method for treating the surface of an object to be treated and a treating apparatus thereof, which is suitably applied, for example, to a electrochemical treatment of the object.
Another object of the present invention is to provide a method for treating the surface of an object to be treated and a treating apparatus thereof, which is capable of avoiding contact between the object and the atmosphere, uniformly activating the surface of the object with precision, and obtaining a good precipitation of metal ion.
A further object of the present invention is to provide an a method for treating the surface of an object to be treated and a treating apparatus thereof, which is capable of rationally carrying out the supply and discharge of the surface treatment fluid and the treatment solution, attaining effective utilization thereof and prohibiting the discharge of the same to the outside of the system, realizing a reasonable system, and enhancing productivity and achieving mass production.
A still further object of the present invention is to provide an a method for treating the surface of an object to be treated and a treating apparatus thereof, which is capable of rationally and safely carrying out the electrochemical treatment operation, miniaturizing the equipment and achieving the cost reduction, and providing a convenient maintenance.
A yet further object of the present invention is to provide an a method for treating the surface of an object to be treated and a treating apparatus thereof, which is capable of omitting the installation of an agitating device in a reaction vessel, miniaturizing the equipment and achieving the cost reduction thereof.
An additional object of the present invention is to provide an a method for treating the surface of an object to be treated and a treating apparatus thereof, which is capable of carrying out the agitation of various surface treatment fluids in the reaction vessel with precision, favorably and rationally carrying out various surface treatments with respect to the object, uniformly supplying ion and obtaining a good finishing of plating.